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Background Extensive evidence supports mechanical thrombectomy using stentrievers (SR) for acute large vessel occlusion (aLVO). Aspiration is also used as a first pass or adjunct technique during clot removal. Here we report technical results from mechanical thrombectomy cases using SR alone, aspiration alone (AD), or a combination of SR and aspiration (SA) as a first pass for aLVO. Methods An institutional stroke database was reviewed for patients presenting to a single academic institution with anterior circulation aLVO and who were treated with mechanical thrombectomy from 2011 to 2017. Patients managed with SR alone, AD, or a combination of these 2 techniques (SA) were identified. The rate of successful recanalization after the first thrombectomy attempt was compared between the 3 groups. Results A total of 353 patients were analyzed, including 215 in SR, 32 in AD, and 106 in SA groups. There was no significant difference for age and admission National Institutes of Health Stroke Scale between the groups. Successful recanalization rates after the first pass were 35.8% in the SR group, 34.4% in aspiration as a first pass technique, and 55.7% in SA, with a statistically significant higher rate of first pass success in the SA group (P = 0.002). Using balloon-guide catheter doubled the rate of successful first pass recanalization from 21.3% to 41.6% in the SR group (P = 0.005); however, the SA technique was more effective for first pass recanalization when compared with an SR and balloon-guide catheter combination (55.7% vs. 41.6%, P = 0.025). Conclusions The combination of SR and catheter aspiration can increase the rate of single pass successful recanalization compared with these techniques individually.

This study comes from my dissertation on the evaluation of student writing. I think I cared and still care about that topic because when I reached a stage where I consciously wanted to write better (I think not until I was an M.A. student in English literature at The University of Chicago), I realized that what was stopping me and what had always stopped me from being able to improve my writing was my inability to articulate what made some pieces I wrote better than others. And my teachers’ comments never seemed to help me very much. By studying texts and teachers’ judgments, I thought, I would be able to find some clues to what good writing was.

Richard Weaver is probably the foremost spokesman for another, more fundamental argument against borrowing from other disciplines, one that goes considerably beyond the observation that people may borrow without sufficient understanding. His argument concerns scientism, “the application of scientific assumptions to subjects that are not wholly comprised of naturalistic phenomena”, such as the humanities. MANOVA looks for main effects and interactions of the independent variables on the dependent variables as a group. When a MANOVA produces a significant result, the researchers can conclude that the independent variables have influenced the dependent variables in some way. Applying the Duncan test, Beach and Wendler found a significant difference in “act inferences” between eighth and eleventh graders, and between both eighth and eleventh graders and college students, but they found no difference between college freshmen and college juniors.

This chapter discusses people’s abilities to think about their own mental activities. Much of the research on metacognition has focused on metacognitive knowledge. People demonstrate metacognitive knowledge when they can accurately describe their own cognitive processes. To understand metacognition fully, one also needs to attend to what is called metacognitive skill, that is, to people’s ability to exercise deliberate control over their own cognitive activities. It is clear, though, that the contrast between what children do when they are asked to write well and what they do when they are asked to write badly is a very sensible and appropriate measure of deliberate metacognitive control of writing skills. The idea of metacognitive skill is a very important one, not just in the primary grades but for adult writers as well. In the late 70’s, the plain speech movement operated on the assumption that good writing is writing that conveys its message as simply as possible.

The simple design using random assignment of the test and control groups and only one treatment and one day to carry it out enabled them to control for such sources of confounding as concurrent events and maturation, testing effects, sampling bias and drop outs. The researchers’ account of how their thinking changed after the original research design had been completed reveals two processes which are quite common in the evolution of research projects. First, as it became more evident that the study would have a reportable outcome, the researchers became more active in considering how the audience might evaluate the study. Second, when the researchers collected their data, it didn’t look quite as they had expected. The assumption lead them to believe that the appropriate way to assess coder reliability would be to use the familiar Spearman rank order correlation.

The brainstorming research has compared individual generation of ideas and group generation, with the relative efficacy of group generation being called into question. In contrast, research has shown that cooperative learning not only facilitates academic achievement but has the potential for improving individual learning as well. The basic idea behind covariate analysis is this: Suppose that the researchers know that some variable of interest, say, writing quality, tends to increase as the the writer’s SAT-Verbal score increases. Thus, the researchers can calculate how well each student did in comparison to how well that student would have been expected to do on the basis of his or her SAT-Verbal score. Covariates can be used to estimate what the difference in performance between the two groups would have been if they had had equal SAT-Verbal scores.

This chapter presents Sarah Warshauer Freedman on two topics, one written for College Composition and Communication and the other for the Journal of Educational Psychology. Freedman describes a study of factors which influence teachers’ judgments of student papers. Although the two articles describe the same study and have the same general organization, they have different audiences and different purposes. The differences in rhetorical stance between these two papers—describing conclusions to practitioners versus arguing for their validity to empirical researchers—are reflected in important structural differences between the papers. The purpose of analysis of variance is to help in drawing conclusions in situations such as this: Suppose that have conducted a study on the vocabulary size of ninth through twelfth grade male and female students. Freedman used analysis of variance to assess the impact of four independent variables, content, organization, sentence structure, and mechanics, on the dependent variable.

Teaching experiments carried out in school settings, as was the case with George Hillocks’ project, offer researchers far more than their usual share of difficulties. Student’s interests are drawn to many things more important to them than the researchers’ concerns: sports, friendships, romance, pressures from home. In addition, practical requirements of classroom management may seriously restrict the time that is available for research or force the researcher to present one treatment to a whole class rather than randomly assigning students within classes to treatments. Hillocks’ study is a model of how to manage a teaching experiment in a complex school environment. Although he had only ten independent observations, his methods of design and analysis allowed him to make very effective use of them. School time is valuable and alternative instructional activities are in competition for the available time.

This study began as a conversation. As we tossed around some ideas for doing a study together, Dick (John Richard Hayes) and I found a mutual interest in task definition. The effect of task definition on revision was one of the items on Dick’s list of research issues waiting to be investigated. Dick’s interest had been piqued by an earlier study that had been abandoned and some previous work on revision (Hayes, Flower, Schriver, Stratman, & Carey, 1987) that had called attention to substantial differences between the basic approaches and strategies that expert and novice writers brought to revision. For me, the question was largely one of application. Given the differences between experts’ and novices’ basic understanding of revision, what should the reseacher do about it? We decided that we wanted to try to nail down the impact of task definition on teaching revision; over the course of a couple meetings we set up a simple experiment.

The iridophores of one type of photophore of the deep sea squid, Pterygioteuthis microlampas were examined with the electron microscope and four different types were found. Three of these types have not been previously described. The regular iridophores of the posterior cup appear to be one-fourth wave length reflectors and redirect the light produced by the photogenic tissue outward. The regular iridophores of the anterior cap have a different spacing and platelet thickness so they apparently pass blue light. The irregular iridophores form a cone around the photogenic tissue and probably randomly reflect light back into the photogenic tissue. The iridophores of the lens have many precisely aligned iridosomes with platelet spacing and thickness so that they appear to collimate light passing through them. It appears that these three types of iridophores reflect, transmit and collimate the light produced in the photophore to match the background illumination hence making an efficient countershading mechanism. A fourth type of iridophore, the wide spaced iridophore, is rarely encountered and probably does not have a significant role in light attenuation in the photophore.

We present a first preliminary molecular analysis of relationships among a sample of living members of the Gryllotalpidae, based on partial nucleotide sequence data of the 16S mitochondrial gene. Our analysis defines five groups that diverged from each other approximately 196 to 284 Mya in the Mesozoic era. This study supports the monophyly of the genus Scapteriscus and its placement in the subfamily Scapteriscinae, as well as the inclusion of the genus Triamescaptor in the subfamily Gryllotalpinae. The monophyly of the large genus Gryllotalpa is not supported, suggesting a revision of the genus is needed.

We report scale model laboratory experiments showing how an impact accelerometer on a planetary probe (based on the Huygens probe Phase A configuration) can provide significant information on the mechanical characteristics of the surface. In particular, solid and liquid surfaces can be discriminated. The density of liquids can in principle be determined from the peak deceleration, thereby providing a constraint on composition, although experimental uncertainties present challenges to the accuracy of this method.

Despite several spacecraft encounters and numerous groundbased investigations, we still do not know much about Jupiter's deep atmosphere; in fact, the Galileo probe results were so different than anyone had anticipated, that we understand even less about this planet's atmosphere now than before the Galileo mission. We formulate four basic questions in Section 1.3, which, if solved, would help to better understand the chemistry and dynamics in Jupiter's atmosphere. We believe that three out of the four questions (explanation of NH3 altitude profile, characterization of hot spots, altitude below which the atmosphere is uniformly mixed) may be solved from passive sounding of Jupiter's deep (∼ tens of bars) atmosphere via a radio telescope orbiting the planet. Question nr. 4 (the water abundance in Jupiter's deep atmosphere) has been singled out by the Solar System Exploration Decadal Survey as a key question, since the water abundance in Jupiter's deep atmosphere is tied in with planet formation models. In this paper we investigate the sensitivity of microwave retrievals to the composition of Jupiter's deep atmosphere, in particular the water abundance. Based upon present uncertainties in the ammonia abundance and other known and unknown absorbers, including uncertainties in clouds (density and index of refraction), and uncertainties in the thermal structure and lineshape profiles, we conclude that the retrieval of water at depth from microwave spectra (disk-averaged and locally) will be highly uncertain. We show that, if the H2O lineshape profile would be accurately known (laboratory data are needed!), an atmosphere with a near-solar H2O abundance can likely be distinguished from one with an abundance of 10–20×solar O based upon the difference in their microwave spectra at wavelengths ≳ 50 cm . This would be sufficient to distinguish between some proposed scenarios by which Jupiter acquired its inventory of volatile elements heavier than helium. If, in addition, limb-darkening measurements are obtained (again, the H2O lineshape profile should be known), tighter constraints on the H2O abundance can be obtained (see also Janssen et al., 2004, this issue).

The temperatures in Jupiter's stratosphere, as measured by the Galileo Atmosphere Structure Instrument (ASI), show fluctuations that have been interpreted as gravity waves. We present a detailed description of these fluctuations, showing that they are not likely to be due to either measurement error or isotropic turbulence. These fluctuations share features with gravity waves observed in the terrestrial middle atmosphere, including the shape and amplitude of the power spectrum of temperature with respect to vertical wavenumber. Under the gravity wave interpretation, we find that wave heating or cooling is likely to be important in Jupiter's upper stratosphere and unimportant in the lower stratosphere.

The Galileo Mission to Jupiter, which arrived in December of 1995, provided the first study by an orbiter, and the first in-situ sampling via an entry probe, of an outer planet atmosphere. The rationale for an entry probe is that, even from an orbiter, remote sensing of the jovian atmosphere could not adequately retrieve the information desired. This paper provides a current summary of the most significant aspects of the data returned from the Galileo entry probe. As a result of the probe measurements, there has been a reassessment of our understanding of outer planet formation and evolution of the solar system. The primary scientific objective of the Galileo probe was to determine the composition of the jovian atmosphere, which from remote sensing remained either very uncertain, or completely unknown, with respect to several key elements. The probe found that the global He mass fraction is. significantly above the value reported from the Voyager Jupiter flybys but is slightly below the protosolar value, implying that there has been some settling of He to the deep jovian interior. The probe He measurements have also led to a reevaluation of the Voyager He mass fraction for Saturn, which is now determined to be much closer to that of Jupiter. The elements C, N, S, Ar, Kr, Xe were all found to have global abundances approximately 3 times their respective solar abundances. This result has raised a number of fundamental issues with regard to properties of planetesimals and the solar nebula at the time of giant planet formation. Ne, on the other hand, was found to be highly depleted, probably as the result of it being carried along with helium as helium settles towards the deep interior. The global abundance of O was not obtained by the probe because of the influence of local processes at the probe entry site (PES), processes which depleted condensible species, in this case H2O, well below condensation levels. Other condensible species, namely NH3 and H2S, were similarly affected but attained their deep equilibrium mixing ratios before the maximum depth sampled by the probe. Processes that might be capable of producing such effects on the condensibles are still under investigation. Measured isotopic ratios of noble gases and other heavy elements are solar, and (D + (Sup 3)He)/H is the same to within measurement uncertainties as in the local interstellar medium. No thick clouds were detected, and in particular no significant water cloud, but the PES location clearly affected the probe measurements of clouds. In fact, the probe data must be understood in the context of the location of the PES, which was within what is termed a 5 micron hot spot, a local clearing in the clouds that is bright near the 5 microns spectral region. The thermal structure at the PES was determined from approximately 1000 km above the 1 bar pressure level (10(exp -9 bars)) to 132 km 1 bar (22bars). The probe showed the atmosphere to have a generally sub-adiabatic temperature gradient (static stability) of = 0.1 K/km to as deep as the probe made measurements. In the upper atmosphere the probe derived a maximum positive vertical temperature gradient of approximately 5 K/km, and maximum temperature of = 900 K. The energy sources producing the warm upper atmosphere have yet to be completely identified. At first glance, Doppler tracking of the probe indicates that the long observed cloud level zonal winds extend to levels at least as deep as the probe made measurements. Zonal wind increases from = 80 m/s at pressures less than a bar to about 180 m/s near 5 bars, and remains approximately constant with depth thereafter. However, there is a question as to whether the winds measured from probe tracking are representative of the general wind field, or are considerably influenced by localized winds associated with the PES.

Galileo Probe Atmospheric Structure Investigation (ASI) pressure and temperature sensor data acquired during the parachute descent phase have been used to derive the static stability structure of Jupiter's troposphere at pressure levels of 0.5–22 bars using three techniques. The first approach utilizes both the p-sensor and T-sensor data, but since the p-sensor's zero offset was significantly affected by the thermal anomaly in the probe, two other approaches using only T-sensor data have also been developed. By making the physically reasonable assumptions of equilibrium descent for the probe and hydrostatic balance of the atmosphere, an algorithm for deriving the background static stability from T-sensor measurements alone is developed. Regions with static stability 0.1–0.2 K km−1 are found at 0.5–1.7 bars, 3–8.5 bars, and 14–20 bars. Between these layers, regions of weaker static stability are present. Mean molecular weight gradients due to the vertical variation of water vapor abundance near the 11-bar pressure level appear to stabilize the atmosphere at this level. Oscillatory structures with vertical wavelength ∼15–30 km and amplitude ∼0.1–0.2 K are observed in the T-sensor data. For pressure

(2000). Planning graduate programs in rhetoric in departments of English. Rhetoric Review: Vol. 18, No. 2, pp. 390-402.

This paper is an introduction to and overview of the accompanying papers in this issue which give detailed results from the Galileo probe mission to Jupiter, including results from the Galileo orbiter and Earth-based observations that are relevant for understanding the probe data and placing them in context. A summary of prior knowledge of Jupiter's atmosphere is also presented. All probe scientific investigations were successful. As anticipated, the Galileo probe results confirm some expectations about Jupiter, refute others, and raise important new questions. The Galileo probe defined the atmospheric thermal structure at the probe entry site from ∼1000 km above the 1 bar pressure level to a depth near 22 bars. During direct atmospheric sampling beginning near 0.4 bar, instruments on the probe measured composition, cloud properties, thermal structure, winds, radiative energy balance, and electrical properties of the Jovian atmosphere. Prior to reaching the Jovian atmosphere, probe instruments measured properties of the inner magnetosphere, observing regions not previously sampled by any spacecraft.

Thermal structure of the atmosphere of Jupiter was measured from 1029 km above to 133 km below the 1-bar level during entry and descent of the Galileo probe. The data confirm the hot exosphere observed by Voyager (∼900 K at 1 nanobar). The deep atmosphere, which reached 429 K at 22 bars, was close to dry adiabatic from 6 to 16 bars within an uncertainty ∼0.1 K/km. The upper atmosphere was dominated by gravity waves from the tropopause to the exosphere. Shorter waves were fully absorbed below 300 km, while longer wave amplitudes first grew, then were damped at the higher altitudes. A remarkably deep isothermal layer was found in the stratosphere from 90 to 290 km with T ∼ 160 K. Just above the tropopause at 260 mbar, there was a second isothermal region ∼25 km deep with T ∼ 112 K. Between 10 and 1000 mbar, the data substantially agree with Voyager radio occultations. The Voyager 1 equatorial occultation was similar in detail to the present sounding through the tropopause region. The Voyager IRIS average thermal structure in the north equatorial belt (NEB) approximates a smoothed fit to the present data between 0.03 and 400 mbar. Differences are partly a result of large differences in vertical resolution but may also reflect differences between a hot spot and the average NEB. At 15 4 bars, probe descent velocities derived from the data are consistently unsteady, suggesting the presence of large-scale turbulence or gravity waves. However, there was no evidence of turbulent temperature fluctuations >0.12 K. A conspicuous pause in the rate of decrease of descent velocity between 1.1 and 1.35 bars, where a disturbance was also detected by the two radio Doppler experiments, implies strong vertical flow in the cloud seen by the probe nephelometer. At p < 0.6 bar, measured temperatures were ∼3 K warmer than the dry adiabat, possible evidence of radiative warming. This could be associated with a tenuous cloud detected by the probe nephelometer above the 0.51 bar level. For an ammonia cloud to form at this level, the required abundance is ∼0.20 × solar.

Full characterization of the polymorphic content of bulk drug chemicals has become increasingly important in the pharmaceutical industry. A multitude of analytical techniques are commonly employed in this process. In this work the feasibility of the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) to the qualitative and quantitative analysis of mixtures of polymorphs is investigated using three known polymorphs of ganciclovir as model compounds. Definitive identification of all three polymorphs is achieved from their ATR-FTIR spectra obtained from the sample in their native state (no sample preparation). Quantitation of polymorphic mixtures is carried out using a partial least-squares procedure. Quantitative results obtained with validation samples for both binary and ternary crystal form mixtures clearly demonstrate the strong potential of ATR-FTIR technique for use in quantitative analysis of polymorphic content of bulk pharmaceutical materials.